Examples - Conversion within and between Systems of Units

Example:
Convert 48 in. (4ft) to meters.

Solution:
The conversion factor is
                        1 m = 39.37 in.

48 in. = 48 in. x (1 m / 39.37 in.)
           = (48 / 39.37) m
           = 1.219 m

Example 1.17:
Convert 6.8 min to seconds.

Solution:
The conversion factor is
                                          1 min = 60 s

6.8 min
= 6.8 min (60 s / 1 min)
= (6.8)(60) s
= 408 s

Example 1.18:
Convert 0.24 m to centimeters.

Solution:
The conversion factor is
                                           1 m = 100 cm

0.24 m
= 0.24 m (100 cm / 1 m)
= (0.24)(100) cm
= 24 cm

Example 1.19:
Determine the number of minutes in half a day.

Solution:
The conversion factors are :
                                              1 day = 24 h
                                              1 h = 60 min

0.5 day
= (0.5 day)(24 h / 1 day)(60 min / 1 h)
= (0.5)(24)(60) min
= 720 min

Example 1.20:
Convert 2.2 yards to meters.

Solution:
The conversion factors are:
                                              1 yard = 3 ft
                                              1 ft = 12 in.
                                              1 m = 39.37 in.

2.2 yards
= 2.2 yards(3 ft / 1 yard)(12 in. / 1 ft)(1 m / 39.37 in.)
= ((2.2)(3)(12) / (39.37) ) m
= 2.012 m

Example 1.21:
How fast in miles per hour is 100 km/h (the speed limit in kilometers per hour)?

Solution:
The conversion factors are:
                                               1 km = 1000 m
                                               1 m = 39.37 in.
                                               1 ft = 12 in.
                                               1 mi = 5280 ft

100 k/h
= (100 km/h)(1000 m / 1 km)(39.37 in. / 1 m)(1 ft / 12 in.)(1 mi / 5280 ft)
= (100)(1000)(39.37)/((12)(5280)) mi/h
= 62.14 mph
or
The simplifyed conversion factor:
                                            1 km/h @ 0.6 mph

100 km/h
@ (100 km/h)(0.6 mph / 1 km/h)
@ (100)(0.6) mph
@ 60 mph

Example 1.22:
Determine the speed in miles per hour of a competitor who can run a 4-min mile.

Solution:
the conversion factor is
                                          1 h = 60 min

1 mi/4 min
= (1 mi / 4 min)(60 min / 1 h)
= 60/4 mi/h
= 15 mph